1. The problem statement, all variables and given/known data the tube has ID of 450mm, t= 6mm, OD= 462mm, pressure is 1.2MPa This is based on ASTM A36 steel, which have Ultimate Tensile strength 400-550MPa Yield Tensile strength 250Mpa Modululs of Elasticity 200Gpa Shear Modulus 79.3GPa Determine the factor of safety at points H and K along the top of the tank and point G on the side by using a) Maximum shear stress theory, b) D.E Von Mises theory I have skipped a prerequisite and this makes real hard on beginning... so please help me 2. Relevant equations 3. The attempt at a solution What I am thinking is using pure tortion on the AD axle, and get T value T = 0.5m x 5000N = 2500Nm or 2.5KNm than find the moment of inertia by using J = pi(OD4-ID4)/2 = 7.1504 x 10-3 m4 at this point, I have G=79.3 x 109, J = 7.1504 x 10-3 m4, and need to find τ by using τ=pT/J = 0.231 x 2500/(7.1504 x 10-3) = 80764.71246 N/m2 which tives τxy on point H K and G Than thinking to find stress of hoop and axial, by using σhoop = pr/t and σaxial = pr/2t on surface, than calculate all and convert into σL and σG, H or K which will give me max stress, than devide the max stress by the σultimate which will give me safety factor Am I on the right track? if not, what did I do wrong? and how should I use D.E Von Mises theory on the question?